Hearing aids have been in use by those with hearing loss or impairment for many decades. Advances in miniaturization of electrical components have allowed hearing aids to become small in size, to the point where the hearing aid can be mounted proximal to the ear itself. Behind-the-ear hearing aids are hearing aids which fit mostly behind the user's ear, remaining at least partially hidden from view.
In most behind-the-ear hearing aids, the main electrical components are located behind the user's ear, with a hearing tube or equivalent protruding from behind the ear to or into the hearing canal itself. In this position, the main electrical components of behind-the-ear hearing aids tend to rest alongside the user's head, proximal to the user's brain.
Many electrical devices output electromagnetic frequency radiation of various strength and frequency. Several of the electrical components of hearing aids emit various wavelengths of electromagnetic radiation. For example, cellular telephones, mobile telephones, pagers, and other small, handheld devices emit electromagnetic radiation in the range of 20 Hz to 1,600 MHz.
Thanks in part to recent anecdotal stories, particularly with respect to cellular telephones, there is a growing public understanding of the dangers of operating small unshielded electronic devices in close proximity to a user's brain.
For a detailed discussion of the human effects from unshielded electronic devices, see “Power Line Radiation, Your Genes, Hereditary Diseases, The Unified Nature Of Electromagnetic Radiation, Energy And Control And The Radiation Limits Of Human Beings” by Daniel Donald Brunda DDG LFIBA MOIF IOM, ISBN: 1-4134-3084-8, hereinafter “Brundal”, which is incorporated herein by reference. Pages 11 and 12 from Brundal, which include Table 1, list exemplary electromagnetic sources and physical injuries thereto attributable, and Appendix B, which is the reference section of Brundal. 
Another publication, “The Design of Safe Electrical Transmission and Distribution Lines, Electromagnetic Powerline Radiation Engineering”, also by Daniel Donald Brunda DDG LFIBA MOIF IOM, ISBN: 1-4010-8922-4, is also incorporated herein by reference.
There is also an informative article by Lynn Quiring, RPh, CCN, NMD of Logical Health LLC, 1163E. Geronimo Place, Chandler, Ariz. 85225, entitled “the Cell Phone Poisoning of America”, hereinafter the “Quiring Article”), which is also incorporated herein by reference. Although focused on cellular telephones, the Quiring Article includes a great deal of information regarding the probable and possible negative effects on humans from EMR, such as produced by small electronic devices.
In addition, manufacturers of cellular telephones and other small electronic devices are using EMR shielding materials to reduce EMR.
Thus, there is a need for electromagnetic radiation (“EMR”) shielding for a behind-the-ear hearing aid, specifically in the frequency range of 20 Hz to 1,600 KHz.
In addition, hearing aids generally work by amplifying sounds for transmission to the hearing canal. These sounds are intentionally audible, but being amplified, may actually be intercepted by a nearby listener or listening device, particularly when there is leakage from around the ear canal. With most conventional, non-behind-the-ear hearing aids, amplified sound from the hearing aid is focused more in the lateral and frontal directions, relative to the user. Thus, a user of most conventional behind-the-ear hearing aids would have a chance of seeing a person or device listening to the amplified sounds from the hearing aid, since these sounds tend to be easiest to hear from the user's sides and front.
In a behind-the-ear hearing aid, however, the speaker is usually located behind the user's ear, and a person or listening device located behind the user can sometimes hear amplified sound, such as due to leakage from the hearing aid encasement, without visual detection by the user. In some cases, a receiver button is inserted into the ear canal and is connected by a wire to the hearing aid body.
Thus, there is a need in an EMR-shielded behind-the-ear hearing aid for shielding against leakage of sound, specifically in the audible frequency range of 20 Hz to 20,000 Hz.